I would suggest you avoid thinking in terms of "business users" and look to specific workflows and applications. There are as many different types of business user as there are grains of sand on the beach, so if you use woolly concepts such as business users you will end up with a generic product for which it is difficult to build a business case. Also, once you have worked out who you are targeting, then the design of the user interface will become more obvious (as you will be able to identify and talk to people who will actually be using the application rather than other IT people who are interested in discussing the hypothetical case).
The most important aspect is that the workforce is far more mobile than ever before and there is indeed a large market for mobile access to documentation. You need to consider whether you are going to follow the existing crowd with Sales Force Automation, Operation Workforce Automation, etc…or identify some new and, as yet, previously unidentified niche.
Also, you need to bear in mind that most mobile devices are unable to render Microsoft Office documents correctly. Where you may find an opportunity is in performing a transformation in alfresco from source format to PDF (or re-sized PDF), so that the document renders nicely on the mobile device. If you have used the iPad for any length of time you will soon realise that it is shockingly inadequate for business use - no filing system, poor rendering of documents, frequently crashes and unable to attach a file to an email.
I wouldn't get too hung up on implementation until you understand who is going to use the solution.
